Noise at the Work Site
Noise is one of the most common workplace hazards. Workers in
many industries and occupations in Alberta are exposed to noise levels
that are so high that their hearing can be damaged. Sometimes the
noise may not even be considered to be noise — such as the very loud
music to which entertainers and food and beverage servers are exposed
in bars and nightclubs. If the sound is loud enough and workers are
exposed to it for long enough, their hearing will be damaged.
Fortunately, work-related hearing loss is preventable.
Employers in Alberta are responsible for minimizing the noise hazard
at their workplaces and must comply with the province’s Occupational
Health and Safety (OHS) legislation. This Safety Bulletin describes
what employers and workers can do to prevent work-related noiseinduced hearing loss.
Health effects
Ears ringing after a day at work? On the way home, does the volume on
the car radio need to be turned up higher than it was on the way into
work? These are two signs of hearing loss, the result of exposure to too
much noise. At first, noise-induced hearing loss affects a person’s ability
to hear higher frequency sounds, but since normal speech does not use
these high frequencies, little hearing change is noticed.
Hearing loss is often
experienced before it
is even noticed.
With continued exposure, hearing deteriorates and eventually the loss
spreads into those lower frequencies involved in speech. Affected
individuals tend to automatically compensate by getting clues from
reading lips without realizing it. Significant hearing loss is often
experienced before it is even noticed.
HS003 — Hearing/Sight
Revised November 2009
1
The body’s reaction to noise is similar to its response when under
stress. Blood pressure and heart rate can increase, and hormone and
blood cholesterol levels can change. Exposure to too much noise can
make a person feel tired. High noise levels can also interfere with
being able to hear important messages in some jobs, causing potential
safety problems unless alternative methods of communication are
used.
Once hearing is lost, it cannot be replaced or repaired. It is vital that
work-related hearing loss be prevented.
Occupational Exposure Limits
Occupational Exposure Limits (OELs) define a worker’s maximum
permitted daily exposure to noise without hearing protection. OELs
take into consideration the loudness of the noise — measured in
decibels (dBA) — and the duration of exposure to that noise —
measured in hours per day. Employers are responsible for making sure
that workers are not exposed to noise that exceeds the OELs and 85
dBA Lex. The OELs appear in Schedule 3, Table 1 of the OHS Code.
Lex is the worker’s level of total exposure to noise in dBA, averaged
over the entire work day and adjusted to an equivalent 8-hour exposure
(based on a 3 dB exchange rate). In other words, a worker exposed to
88 dBA for 4 hours or 91 dBA for 2 hours would be exposed to
85 dBA Lex (an exposure equivalent of 85 dBA for 8 hours).
OELs take into
consideration the
loudness of the noise
— measured in
decibels (dBA) — and
the duration of
exposure to that
noise.
HS003 — Hearing/Sight
Revised November 2009
2
Figure 1:
Schedule 3, Table 1 of the OHS Code Occupational exposure limits for noise
Exposure level
(dBA)
82
83
84
85
88
91
94
97
100
103
106
109
112
115 and
greater
Exposure duration
16 hours
12 hours and 41minutes
10 hours and 4 minutes
8 hours
4 hours
2 hours
1 hour
30 minutes
15 minutes
8 minutes
4 minutes
2 minutes
56 seconds
0
Noise management program
Where workers are exposed to “excess noise” (noise exceeding the
OELs), the employer must develop and implement a Noise
Management Program. Such a program consists of the following
elements:
Educating workers — this includes how noise-induced hearing loss
occurs and how workers can protect themselves.
Measuring and monitoring sound levels — what needs to be done to
protect workers depends on the level and type of noise at the
workplace. Measuring sound levels identifies noise sources and those
workers most likely to be exposed to noise exceeding the OELs.
Posting of suitable signs — where the noise level exceeds 85 dBA.
Controlling noise exposure — worker exposure to noise can be
reduced through
(a) engineering controls;
(b) administrative controls; or
(c) by providing workers with appropriate personal hearing protection.
Each of these approaches are described more fully further on in this
Bulletin.
HS003 — Hearing/Sight
Revised November 2009
3
Hearing protection devices — this includes selection, use and
maintenance of the equipment.
Conducting audiometric tests — workers hearing needs to be tested to
determine the extent of existing hearing loss and to monitor for ongoing changes in hearing ability.
Evaluating the program — verifying that the program is doing what it
is intended to do – prevent work-related hearing loss. Verification
must be done at least annually.
Educating workers
All workers exposed to noise levels exceeding the OELs need
instruction about the noise hazard, how it can affect their health, how
to protect themselves, their responsibilities and their role in the Noise
Management Program. Worker compliance with the employer’s
program should be a condition of employment.
Regular and on-going education for workers helps to increase their
understanding of the importance of hearing conservation — both at
work and when exposed to high noise levels at home, at sports and at
entertainment events.
Figure 2 summarizes some of the most frequently heard reasons why
workers do not use their hearing protection.
Figure 2 Hearing protection excuses and facts
Excuse
Fact
“I’m used to noise.”
The only way you can be “used to noise” is if your
hearing is so damaged you’re literally deaf to it.
“Hearing protection is uncomfortable.”
Hearing protection takes a bit of getting used to,
just like a pair of safety glasses or new safety
boots. The hearing protection might feel odd at
first, but after 2 weeks (at most) you’ll hardly notice
you’re wearing it.
“My hearing’s already changed.”
True, hearing protection can’t bring back the
hearing you’ve lost. It can, however, save the
hearing you have left. The risk of hearing damage
doesn’t lessen as you get older.
“I’m too old to start now.”
HS003 — Hearing/Sight
Revised November 2009
4
Excuse
Fact
“I won’t hear what people are saying to me.”
Wearing hearing protection in a noisy environment
often makes conversation easier to distinguish.
Your ability to hear people may improve when
using the hearing protection.
“I’ve never used hearing protection and my hearing
is as good as ever.”
The terrible thing about noise-induced deafness is
that you don’t notice it until it’s too late. You have to
be wise before the event. The fact that you haven’t
been affected so far doesn’t mean that you’re
immune to noise damage.
Measuring and monitoring sound levels
Part of a Noise Management Program is to identify noise hazards in
the workplace and those workers most likely to be exposed to noise
exceeding the OELs. This is done by conducting a survey in which
sound levels are measured and the duration of worker exposures in the
various work areas are determined. These results establish the need for
a program and its scope.
The exposure assessment must be done in accordance with the
Canadian Standards Association (CSA) Standard Z107.56-06,
Procedures for the Measurement of Occupational Noise Exposure.
The person who conducts and interprets the exposure assessment must
be competent as defined in the OHS Code. In addition, the equipment
used to measure noise exposure must meet the requirements of one of
the Standards listed in section 219(3) of the OHS Code.
An initial noise survey should be performed in any work area where
workers must significantly raise their voices in order to be heard over
the background noise. The survey should include work areas that are
indoors, outdoors, and in mobile equipment. If the results of this initial
survey indicate that no workers are exposed to noise levels exceeding
the OELs, then periodic surveys will identify if conditions have
changed over time. These periodic surveys must be performed when:
(a) new noise-generating equipment or work processes are introduced;
(b) old equipment seems to get louder over time;
(c) work practices and/or work procedures change; and
(d) workers complain of ringing in the ears, temporary changes in
hearing, or increased levels of noise in their work area.
HS003 — Hearing/Sight
Revised November 2009
An initial noise survey
should be performed
in any work area
where workers must
significantly raise their
voices in order to be
heard over the
background noise.
5
If the noise survey identifies workers exposed to noise that exceeds the
OELs, then the OHS Code requires the employer to take action to
reduce noise exposure.
Controlling noise exposure
Section 217 of the OHS Code requires that noise levels be no more than
85 dBA, or as low as reasonably practicable, when designing or
constructing the following:
ƒ a new work site
ƒ significant alterations to an existing work area
ƒ introduction of a work process
ƒ introduction of significant equipment.
When reducing noise exposure, preference is given to engineering
controls, then administrative controls, and finally the use of
appropriate personal protective protection. Engineering controls
minimize or eliminate exposure by altering or removing the source.
Administrative controls control exposure by modifying the
circumstances of the worker’s exposure. Personal protective protection
reduces exposure by protecting the worker when the other approaches
have not reduced the hazard to an acceptable level.
(a) Engineering controls
Noise can be reduced or eliminated by using one or more of the
following approaches:
(i) Substitution
ƒ replace noisy equipment or machinery with quieter
equipment or machinery
ƒ replace noisy processes with quieter ones
(ii) Modification
ƒ modify the way in which the equipment operates so that it
generates less noise: e.g. operate the equipment at a slower
speed, improve lubrication, balance rotating parts, reduce
vibration through dampening or bracing
HS003 — Hearing/Sight
Revised November 2009
6
(iii) Isolation
ƒ isolate workers from a noisy area by having them work in
an enclosed room
ƒ segregate noisy areas with sound barriers and partitions
ƒ isolate noisy equipment in an enclosed room
ƒ place sound absorbent material and covers around noisy
equipment
(iv) Maintenance
ƒ maintenance of equipment and the engineering controls that
have been implemented is very important or the
improvements in noise level will be lost
Dealing with noise at its source can significantly reduce the hazard or
eliminate it altogether. With sufficient noise reduction, the need for
administrative controls or personal protective protection is eliminated.
Engineering controls must always be considered during the design
stage of a new facility or the expansion of an existing facility.
Reducing noise at source after start-up of a new or expanded facility is
usually more costly than adding engineering controls initially. If
equipment and machinery are quiet to begin with, steps to protect
workers from workplace noise may be unnecessary.
(b) Administrative controls
Administrative controls include rotating work schedules or changing
production schedules so that the amount of time that a worker is
exposed to noise is within acceptable limits. When noise levels cannot
be sufficiently reduced or eliminated through engineering controls,
administrative controls can still be used to significantly reduce worker
exposure.
(c) Providing appropriate personal hearing protection
If reductions in noise levels and exposure times have not reduced
worker exposures below the OELs, then appropriate hearing protection
must be provided to those workers. Hearing protectors must meet the
requirements in CSA Standard Z94.2-02, Hearing Protection Devices
– Performance, Selection, Care and Use. CSA classifies muffs and
earplugs as Class A, B, or C or Grade 1, 2, 3, or 4 based on the level of
protection they provide. Schedule 3, Table 2 of the OHS Code
summarizes the minimum levels of protection required.
HS003 — Hearing/Sight
Revised November 2009
Dealing with noise at
its source can
significantly reduce
the hazard or
eliminate it altogether.
7
Figure 3
Schedule 3, Table 2 of the OHS Code Selection of hearing protection devices
Maximum equivalent
noise level
(dBA Lex)
≤ 90
≤ 95
≤ 100
≤ 105
≤ 110
> 110
CSA Class of hearing
protection
CSA Grade of
hearing protection
C, B or A
B or A
A
A
A earplug +
A or B earmuff
A plug + A or B earmuff
and limited exposure time
to keep sound reaching the
worker’s ear drum below
85 dBA Lex
1, 2, 3, or 4
2, 3, or 4
3 or 4
4
3 or 4 earplug +
2, 3, or 4 earmuff
3 or 4 earplug + 2, 3, or 4
earmuff and limited
exposure time to keep
sound reaching the
worker’s ear drum below
85 dBA Lex
To be of value, hearing protection must be used properly and be worn
when the worker is in the noisy area(s). For maximum protection,
hearing protection must make a tight seal within the ear canal or
against the side of the head. Modifying hearing protectors to reduce
discomfort e.g. by drilling holes in earcups, by reducing headband
tension of muffs, or by trimming or removing flanges on premoulded
earplugs can seriously compromise effectiveness. Hearing protection
must also be compatible with other equipment such as hardhats, safety
eyewear, eyeglasses, and masks so that it provides the level of
protection originally intended.
For maximum
protection, hearing
protection must make
a tight seal within the
ear canal or against
the side of the head.
Conducting audiometric tests
The OHS Code requires employers to have workers who are exposed
to noise that exceeds the OELs undergo audiometric testing. The
purpose of this testing is to have a baseline measurement of the
worker’s hearing and to then monitor their hearing at regular intervals
afterwards to detect changes in hearing ability. The employer is
responsible for the costs associated with this testing.
HS003 — Hearing/Sight
Revised November 2009
8
Audiometric tests must be performed by a qualified audiometric
technician who has taken a course approved by Alberta Employment
and Immigration. The OHS Code describes how, when, with what
equipment, and under what conditions the tests are to be performed.
The OHS Code also stipulates that audiogram records must be kept on
file for 10 years. Audiograms are confidential medical records and
cannot be given to the employer. The employer must ensure that the
audiogram and the worker’s medical history are under the sole control
of a health professional designated under the OHS Code, subsection
223(2)(a). Audiograms can only be released with the worker’s written
consent. Workers’ audiograms that show abnormalities must be
reviewed by either a physician or audiologist. The employer is
responsible for paying for these services.
Workers’ audiograms
that show
abnormalities must be
reviewed by either a
physician or
audiologist.
For more information
http://employment.alberta.ca/documents/WHS/WHS-PUB_hs005.pdf
Audiometric Testing: Information for Employers and Workers
The audiometric testing component of the Noise Management Program
provides an excellent opportunity to educate workers. Standard
procedures for audiometric testing include discussing the results of
hearing tests with the worker tested. The importance of noise control
and wearing hearing protection can also be reviewed. This provides
the technician with an opportunity to check the worker’s hearing
protection to ensure good fit and an adequate level of protection. These
sessions are often an opportunity to motivate workers to protect their
hearing both on and off the job.
In addition to meeting regulatory requirements, there are advantages to
employers in having audiometric tests performed. Baseline and
periodic tests document whether or not a worker is losing hearing with
a particular employer. This can be important in determining the impact
of hearing loss in particular industries, and subsequently, in an
employer’s Workers’ Compensation Board assessment rates.
From the worker’s perspective, audiometric tests can alert the worker
to changes in their hearing. Such changes point to the need to examine
the hearing protection provided to make sure that it is adequate and
being used properly. Once this has been verified, the worker should
consider if the hearing loss is due to non-work-related activities.
HS003 — Hearing/Sight
Revised November 2009
9
Evaluating the program
The Noise Management Program must be evaluated annually to verify
its effectiveness. The extent of the evaluation should be based on the
sophistication and complexity of the program.
The key question to be asked is: “Is the Program preventing workrelated noise-induced hearing loss?” Analysis of the results of the
audiometric tests can provide a good indicator of the Program’s
effectiveness. Results can be compared from year to year so that trends
can be observed. These results can also show trends for specific
occupations, for various processes, for different departments, or
between different work sites. Specific problems can be identified when
results are divided into these groupings.
All components of the Program must be evaluated for compliance with
the employer’s policies and procedures, completeness and accuracy,
and compliance with the OHS Code.
HS003 — Hearing/Sight
Revised November 2009
10
Contact us:
Province-Wide Contact Centre
Web Site
Edmonton
780-415-8690
Throughout Alberta
1-866-415-8690
www.worksafely.org
(Toll Free)
Deaf or hearing impaired
ƒ Edmonton 780-427-9999
ƒ Other locations 1-800-232-7215
(Toll Free) Getting copies of OHS Act, Regulation & Code:
Queen’s Printer
Workplace Health and Safety www.qp.gov.ab.ca
Edmonton
780-427-4952
http://employment.alberta.ca/whs‐ohs Call any Government of Alberta office toll-free
Dial 310-0000, then the area code and telephone number you want to reach
© 2009-2010, Government of Alberta, Employment and Immigration
This material may be used, reproduced, stored or transmitted for non-commercial purposes. The source of this material must be
acknowledged when publishing or issuing it to others. This material is not to be used, reproduced, stored or transmitted for
commercial purposes without written permission from the Government of Alberta, Employment and Immigration. This material is to
be used for information purposes only no warranty express or implied is given as to the accuracy or the timeliness of the material
presented.
HS003 — Hearing/Sight
Revised November 2009
11